In the reaction CuO + H₂ → Cu + H₂O, which is the correct identification of oxidation and reduction?
Answer and explanation
Correct answer: Hydrogen is oxidised and copper(II) oxide is reduced
Oxidation can be identified by an increase in oxidation number or addition of oxygen, while reduction involves a decrease in oxidation number or removal of oxygen. In H₂, hydrogen has oxidation number 0; in H₂O it becomes +1, so hydrogen is oxidised. Copper in CuO is +2 and becomes elemental copper with oxidation number 0, so CuO is reduced. Since both occur together, this is a redox reaction and option A is correct.
Frequently asked questions
What is the correct answer to this question?
Hydrogen is oxidised and copper(II) oxide is reduced
Why is this the correct answer?
Oxidation can be identified by an increase in oxidation number or addition of oxygen, while reduction involves a decrease in oxidation number or removal of oxygen. In H₂, hydrogen has oxidation number 0; in H₂O it becomes +1, so hydrogen is oxidised. Copper in CuO is +2 and becomes elemental copper with oxidation number 0, so CuO is reduced. Since both occur together, this is a redox reaction and option A is correct.
Which subject and chapter does this question cover?
This is a Class 10 Science question. Chapter: Chemical Substances – Nature and Behaviour. Topic: Chemical Reactions and Equations.
